DESCRIPTION:(adapted from applicant's abstract) The investigators propose to expand upon a preliminary finding that one or more regions of classic auditory association cortex posterior to A1 are sites of multisensory convergence, in that they respond to somatosensory stimuli, as well as sounds. This surprising finding disputes a prevailing view that multisensory integration is confined to specialized, higher order "association" structures. It also bears on the fundamental question of whether auditory and somatosensory systems have "what" and "where" divisions like those proposed for the visual pathways. Anatomical tracer studies, in conjunction with standard multiunit / single unit mapping procedures in anesthetized monkeys and with multielectrode studies in awake monkeys will address 3 specific aims. 1) To delineate the somatosensory map(s) and determine of the relationship of somatosensory representation to previously defined auditory fields. 2) To identify the anatomical source(s) of somatosensory input. 3) To determine the functional significance of auditory-somatosensory co-representation. These experiments will evaluate the hypotheses that the caudal belt and parabelt regions of auditory cortex are involved in auditory localization and that somatosensory-auditory interactions contribute to this function.